Emphysematous chronic obstructive pulmonary disease (COPD) is an irreversible lung disease of increasing prevalence for which effective disease modifying therapy is not available. Patients with COPD exhibit dysregulated and exaggerated inflammatory and immunologic responses. Recent studies have shown that the aminopeptidase activity of the leukotriene A4 hydrolase (LTA4H) enzyme may play crucial roles in the process of resolving inflammation. We have independently demonstrated effective protection of murine lungs against COPD by selectively augmenting the LTA4H aminopeptidase activity with 4MDM, a selective small molecule activator of the LTA4H aminopeptidase activity. When COPD was induced with cigarette smoke, treatment with 4MDM significantly reduced severity of COPD as determined by pre-mortem physiologic and post-mortem anatomic assessment. On the basis of these findings, we believe that 4MDM can serve as a lead molecule for the discovery of novel anti-inflammatory agents to treat COPD. Therefore, we propose specific aims to better understand the target LTA4H enzyme structure, discover new activators of the LTA4H aminopeptidase activity, and determine the effect of these compounds in the pathogenesis of COPD. We believe that our proposed work and expected outcomes will provide potential first-in-class drugs to treat patients with COPD.